Nowadays, integrated circuits may comprise a plethora of different sensors, such as ambient light (AL) sensors, temperature (T) sensors, gas sensors, relative humidity (RH) sensors, specific analyte detection sensors, and so on.
Integrated circuits of this kind have a wide range of applications. For example, they can be used in the field of supply chain management to track and monitor the freshness of food and beverages. They can also be used as environmental sensors, for example as part of a heating, ventilation and air conditioning (HVAC) system in an automobile or in a building (e.g. a Smart Building). Additional applications include those in agricultural (e.g. the sensing of environmental conditions in greenhouses) or in medical fields. Their provision in mobile communications devices such as mobile telephones, tablets or laptops can also enable a wide range of further applications that require measurements of local environmental factors.
The provision of sensors in integrated circuits of this kind allows devices to be produced that have a small form factor, and which can be manufactured cheaply in large numbers using established semiconductor processing techniques.
Due to their small form factor, integrated circuits of this kind can easily be included in Radio Frequency Identification (RFID) tags, allowing for easy programming and readout.
There is a constant desire to diversify the sensor functionality integrated into an IC to add further functionality to a device utilizing the IC. For instance, WO 2009/087531 by the present applicant discloses an IC having a light sensor that can detect both the intensity and direction of incident light, e.g. to compensate the output of a display device for ambient lighting conditions to improve the user experience of the display device. To this end, the light sensor comprises a dielectric layer, wherein the dielectric layer is substantially transparent to the incident light as well as a plurality of photo detectors coupled relative to the dielectric layer for detecting the incident light through the dielectric layer. A plurality of stacks of opaque slats embedded within the dielectric layer approximately parallel to an interface between the dielectric layer and the photo detectors are also present to define tapered light apertures between adjacent stacks of opaque slats.
Such a light sensor requires a relatively complex arrangement of tapered stacks of slats to make the light sensor directionally sensitive. There exists a need to simplify the design of such a light sensor.